Modifying the tab-content CSS

We now modify the CSS styles for the tab-content class in the mystyles.css file as follows: 

.tab-content {
  border-left: 1px solid #ddd;
  border-right: 1px solid #ddd;
  border-bottom: 1px solid #ddd;
  padding: 10px;
}

This modification adds a 1px border to the tab content which joins with the upper border introduced by the tab navigation element to give a clean tab like appearance.